"use client";

/**
 * Auth → Chat 同步器
 *
 * Chat machine 不直接感知 Auth machine；这里作为根级桥接器，持续监听
 * loginStatus 变化并派发 chat 鉴权生命周期事件。这样页面组件只负责 UI，
 * 不再承担全局状态同步职责。
 */
import { useEffect, useRef } from "react";
import { shallowEqual } from "@xstate/react";

import { AuthStorage } from "@/data/storage/auth";
import {
  selectAuthIsLoading,
  useAuthSelector,
} from "@/stores/auth/auth-context";
import { useChatDispatch } from "@/stores/chat/chat-context";

export function ChatAuthSync() {
  const authState = useAuthSelector(
    (state) => ({
      hasInitialized: state.context.hasInitialized,
      isLoading: selectAuthIsLoading(state),
      loginStatus: state.context.loginStatus,
    }),
    shallowEqual,
  );
  const chatDispatch = useChatDispatch();
  const prevSessionKeyRef = useRef<string | null>(null);

  useEffect(() => {
    if (!authState.hasInitialized || authState.isLoading) return;

    const sessionKey = authState.loginStatus;
    if (prevSessionKeyRef.current === sessionKey) return;

    if (authState.loginStatus === "notLoggedIn") {
      prevSessionKeyRef.current = sessionKey;
      chatDispatch({ type: "ChatLogout" });
      return;
    }

    if (authState.loginStatus === "guest") {
      prevSessionKeyRef.current = sessionKey;
      chatDispatch({ type: "ChatGuestLogin" });
      return;
    }

    let cancelled = false;
    void (async () => {
      const tokenR = await AuthStorage.getInstance().getLoginToken();
      if (!cancelled && tokenR.success && tokenR.data) {
        prevSessionKeyRef.current = sessionKey;
        chatDispatch({
          type: "ChatUserLogin",
          token: tokenR.data,
        });
      }
    })();

    return () => {
      cancelled = true;
    };
  }, [
    authState.hasInitialized,
    authState.isLoading,
    authState.loginStatus,
    chatDispatch,
  ]);

  return null;
}